Means for preventing premature firing of depth charges



MEANS FOR PREVENTING PREMATURE FIRING OF DEPTH CHARGES Filed Feb. 13,1946 Sept. 30, 1952 J. L. ANDREWS 3 Sheets-Sheet l S m R MD 3N A m L. 43 w 2 4 9 5 l B w 54 5 l d 3 l 5 5 24 9 5 7 3 3 3 \1 l1 l L I a Mdmv HIHN L L u 6 1 I 2 4 4 n 3 l 3 6 5 l fi A l 6 0 M55 5 2 3 3 i 2 Sept. 30, JL AN MEANS FOR PREVENTING PREMATURE FIRING OF DEPTH CHARGES 3Sheets-Sheet 2 Filed Feb. 13, 1946 S W E m R 0 SN A L IU- Sept. 30, ANQE S MEANS FOR PREVENTING PREMATURE FIRING OF DEPTH CHARGES 3Sheets-Sheet 3 Filed Feb. 13, 1946 gwua/wbo'v J. L. ANDREWS woman;

Patented Sept. 30, 1952 'YUNITED STATES PATENT 2,612,107 OFFICE MEANSFOR- PREVENTING PREMATURE FIRING OEDEPTHCHARGES This invention relatesgenerally to a depth charge and more particularly to new and improvedmeans for preventing firing thereof in response to shocks such as arereceived, for example, by the depth charge upon impact with the waterduring the launching operation thereof.

amended April 30, 1928; 370 0. G. 757) In certain types of depth chargesheretofore employed in service and having, among other elements, certainelements adapted to be moved relative to each other in response to thepressure of the surrounding water to fire the depth charge, ithas beendiscovered that in certain positions of the depth charge at the momentof impact sufficient inertia forces may be developed which cause theseparts to move to their firing positions, thereby to fire the depthcharge prematurely.

In the device of the present invention this difficulty has been overcomeby employing a toggle arrangement having a pair of inertial elementssecured thereto for restraining the movement of the hydrostatic elementto the firing position until the deceleration of the depth charge hassubsided during movement of the depth charge through the water.

In accordance with the preferred form of the invention, this isaccomplished by employing the inertial forces set up within the inertialmembers at the moment of impact of the depth charge with the surface ofthe water to prevent premature movement of the toggle joint and thehydrostatic element to the firing position as the result of theaforesaid impact or as the result of a shock received through thesurrounding water caused by the explosion of another depth charge or thelike within the vicinity'of the device.

An object of the present invention is to provide new and improved meansfor generatingin'ertial forces adapted to prevent the inertial forces ofthe firing parts from causing movement thereof upon impact of the depthcharge with the water.

Another object is to provide inertial means for locking the firingelements of the depthcharge against movement upon impact of the depthcharge with the water without interfering with the normal operation ofthese parts in response to an increase in the hydrostatic pressure ofthe surrounding water.

Another object is to provide a depth charge having an inertialcontrolled toggle linkage for preventing firing thereof in response toshocks received thereby in which means are provided for reducing theinertial forces set up within the inertial elements at the moment ofimpact of the depth charge with, the surface of the water.

A further object is to provide new and improved means for preventingfiring of a depth charge in response to shocks received thereby whichemploys a minimum number of parts.

I Still other objects, features and advantages of. 1 the presentinvention are those relating to the inder 2| which is held in fixedspace relation novel construction combination and arrangement of partsas will best be understood from the following description of a preferredembodiment of the invention, reference being had to the accompanyingdrawings wherein:

Fig. l-is a view in elevation and partly in section of a depth chargepistol employing the inertial locking means of the present inventionaccording to thepreferred embodiment thereof;

Fig. 2 is a view of the depth charge pistol taken substantially alongthe lineZ-Z of Fig. l;

Fig. 3 is a sectional view partly broken away along the line 3-3 of Fig.l;

Fig. 4 is a view similar to Fig. l and illustrating the inertial lockingmeans in the unlocked position thereof; and

Figs. 5, 6 and 7 are detail views of one of the weights comprising theinertia locking means.

In the accompanying drawings, the numeral l0 generally designates adepth charge pistol suitable for:use with a depth charge. of a type suchas that disclosed and claimed in'the copending application of Harry H.Moore et al. for Depth Charge Firing Mechanism, Serial No. 474,354,filed February 1, 1943; The pistol disclosed in the present application,except for the inertia locking means hereinafter to be described, issubstantially the same as that disclosed in the copending applicationand reference may be had thereto for details of construction andoperation.

It will sufiice for purposes herein, therefore, to

briefly point out that the pistol comprises a cylindrical casing. l l towhich one end, not shown, of

Cup-shapedmember l3 has mounted thereon a supporting block assembly I4for a plurality of leaf springs l5, one of which carries on the endthereof a firing pin l6. As the cup-shaped member is drivenprogressively by the bellows as the depth charge descends through thewater, the

firing pin is moved. along the, inclined portion ll of a cam [8 untilthe pin passes beyond the.

upper end of the cam, thereby causing the pin to strike a percussion capl9 to ignite an explosive train and booster charge which in turn firesthe main explosive charge of the depth charge.

A booster charge is contained within the cylwith flange 23 by thespacing collars and screws 20, the tubular member 22 being interposedtherebetween. Flange 23 is fitted into fixed registered engagement withthe tubular casing H as at 24. The flange 23 also supports a cylindricalmember 25 which is telescopically fitted within member I3 and having aportion of the explosive train arranged therein-and through which thepercussion capt'io'perates to ignite the: explosive train, thepercussion cap [9 and cam I8 adjacent thereto both being supported byand secured to.- the member 25.

A piston 26 is telescopically fitted-within 'cylindrical member 25 andcarries axially thereof an electroresponsive detonator 21, 3,-which I vis electrically connected to terminals 28 forming a part of a magneticinfluence. system adapted to fire the detonator when the depth. chargemoves within the vicinity of a submarine. The

piston is adapted to be move'd by the bellowssuch:

that the detonator is moved into-cperatiVe reIation with the explosivetrain during descent of the'depth charge. butprior' to movement of thefiring. pininto its"firingposition,- whereby the and limited by surfaces51.

3 tosim'ake maximum use of inertia even though dimensional' variationsexist in the mechanism.

The springs 54 also permit the use of wide commercia'ltolerances withoutimpairing the operait tion offthe mechanism.

The, levers 35 and 36 have attached thereto,

' or made integrally therewith, the weights 55 and -56--so mountedandarranged thereon as to predepth chargesmay'be fired by the influencemeans.

prior to self-destruction thereof which is accomplished at apredetermineddepth of submergence by 'th'e hydrostatically controlled:percussion means; e Key'and'slot means 29" and 3| are employed toprevent relative rotation between piston. 26 and-Fmem'ber and, simlarly,aslot 32-.is formed in member 25 torec'eive the tip of a'shoulderscrew:33 to' prevent relative rotation between cupmember l3 and member25 whereby the angular orientation of the detonator with respect totheexplosion Ttrainis not disturbed during movementof the piston. v

The inertia locking means for preventing movement of the firing pin inresponse to shocks received by the depth charge during launching thereofor'from' other causes such" as result from the inadvertent or accidentaldropping thereof or from countermine shocks will now be described. Thelocking means comprises a toggle system of'levers forv interconnectingthe cup? member l3 and flange 23 and a plurality. of. inertia responsivemembers carried by the levers in such a mannerfias to" cause the leversystem to effect a restraining action between the cup member l3 andflange 23: whereby shocks received by the depth charge-are inefiectiveto actuate the hydrostatic: element to thefiring'position regardless ofthe direction' 'from which the shocks are received. Under" normal.conditions, however, the cup.- member is free to drive the levers andinertia; members so as'to produce movement of the. firing. pin to" firethe depth charge, as heretofore described. Yieldable' means comprising apair of springs'is employedwith the lever system to prevent damage tothe' pistolby reason ofinertia forces developed by the inertia memberswhen shocks 'arereceived in a direction to set up forces tending todrive the: cup-member in an opposite direction from its normalfl'ring'movement.

'The'lever system includes a T-shaped member 34 'which is secured tocup-member l3. as by the shoulder screw 33. A pair of leverarms 35 and36 are pivotally secured to the T-member 34 as at 3Tand38:respectively.Arms 35 and 36, in turn; have pivotally securedthereto'as at 39V and41*a; pair'of levers 42 and 43 respectively. These levers, in turn, arepivotally secured as at 44 anda45lwithinaslotted member 46' havingapertured' ears 4'!" and 48' through. which shoulder screws and 51'slidably pass; These: screws are: securelytightened into a (i-shapedmember 52 -whihz is secured: to flange member 23: as; by. bolts 53Azpair; ofsprings 54 arecoiledabout screws. 49 and respectively so asto. normally yield'ablyfurge the'slotted' member'rinto substanetiallyabutting relation:.with c.-shaped;member:52;

vent-alignment of-the center lines of the levers as used in combinationwith the levers 42 and 43;: vThis is accomplished-by mountingeach of theweights such that surface 51 thereof forms an angle with the center lineextending through the pivots of. the lever aflixed thereto wherebythe-extending portion 58 of each weightengages: the lever 42or43-cooperating with the lever arms? 35 or 36 respectively before thecenterllinesof these levers move into alignment. as-best seen in;Fig. 1. Thus; a dead center condition ofsthe; lever system .is avoidedwhereby thesystem may beactuated by the cup-memben l3- to-movetheweights outwardly, as best seeninFig. 4,, as the cup-member ismovedfrom itsposition asseen. in Fig. 1 bythe hydrostatic pressure, acting,-there-' on;

In the event that-shocks are received bythe'rdepthcharge in such adirection as to tend. to move the cup member l3-andfiring pin I6 carriedthereby-toward its firing position;v inertia forcesalsoact-upomweights55 and 56, which:

forces tend tomove the weights inwardly, thereby to'lockthe lever systemand prevent movement. of cup member l3. Shocks received' by thecupshaped member l3 and parts secured thereto? tending to move the cupmember'in the opposite direction also tend to move the" Weightsqoutwardly. If themember 41 were rigidly secured togC-shaped member 52,these shocksmight pro-' duce stresses in the levergsystem,particularlyat shoulderscrews 49 and 5 I sufiicient to rupture orotherwise-damagethe lever system. This conditionis avoided by theyieldable mountingbe tweenslotted member 46 and C-shaped member 52',which yieldable mounting is adapted to absorb such shock effectssufficiently to prevent. damage to 'the lever system and mountingstherefor.

The weights 55. and 56 may be so proportioned as.-- to fit intoanysuitable type depth'charge' pistol. In. the pistol I0 disclosedherein;for-example, the inner surface 59- of. each weightiis fromed. to= fitabout-the cylindricalmemberi 25-,1

inner-surface 60 iscuiwed so as toclear cup member l3 when the-leversystem is fully'actueated; and the outer surface til thereofis curvedinsuch a manneras to fit inside the casing H and allow movement of thelevervsystem'without mechanical interference.

"While the invention has been described with particularity as to aspecific example thereof comprising -a---.p1urality of weights andlevers adaptedto fulfill theaforestated objects of the invention, itwill be understood that this hasbeen: done for purposes of disclosureand that various changes'and'substitutions will 'be'readily apparentto-those skilled in the art; after? under standing the invention, andthat the terms em.-

ployed in the claims are to be consideredaswords' ofdescription-ratherthan of limitation;

-The; invention herein described and claimed.

may be manufactured and used by or for the Government of the UnitedStates of America for governmental purposes without payment of anyroyalties thereon or therefor.

What is claimed as new and desired to be secured by Letters Patent ofthe United States is:

1. In a depth charge of the character disclosed, the combination of asupport, means including a firing member adapted to be moved within saidsupport to a firing position under pressure of the surrounding waterthereby to fire the depth charge, a toggle linkage including pairs ofmutually connected links, one end of each of said pairs of links beingconnected to said member and the other end of each of said pairs beingconnected to said support and adapted to be flexed by the member as themember moves to the firing position, and a plurality of inertia devicescarried by said toggle linkage, one of said inertia devices beingattached to one of the links of each pair of links and responsive toshocks received by the depth charge to resist flexing of the linkage forpreventing movement of the firing member to said firing position inresponse to said shocks, said inertia devices engaging the other ones ofsaid pairs of links to prevent looking of said links on dead center.

2. In a depth charge of the character disclosed, the combination of adepth charge pistol having a supporting structure and a firing memberadapted to be moved relatively thereto under pressure of the surroundingwater into a predetermined firing position thereby to fire the depthcharge, a lever pivotally secured at one end thereof to said member, asecond lever pivotally secured at one end thereof to said first namedlever and at the other end to said supporting structure, said leversbeing arranged such that their pivotal centers are slightly out ofalignment when the firing member is in an initial unmoved positionwhereby said levers are free to move further out of alignment as saidfiring member moves to said firing position, and an inertia devicecarried by one of said levers and arranged thereon, said inertia devicebeing adapted to engage the other of said levers thereby to prevent thelevers from being moved into a position such that their pivotal centersare in dead center alignment, said inertia device being urged into saidengagement with the other of the levers in response to a shock forcewhich urges the firing member toward the firing position thereby toprevent movement of the member thereto in response to said shock force.

3, In a depth charge of the character disclosed, the combination of adepth charge pistol having a supporting structure and a firing memberadapted to be moved with respect thereto under pressure of thesurrounding water from an initial position into a predetermined firingposition thereby to firethe depth charge, a pair of toggle jointscomprising a pair of levers for preventing movement of the firing memberto said firing position in response to a shock received by the depthcharge, each of said levers bein secured at one end thereof to saidmember, and a second pair of levers, each of said second levers beingpivotally secured at one end thereof to a lever of said first named pairof levers respectively, a movable support pivotally secured to the otherend of each of said second levers, means of yieldably securing saidmovable support to said supporting structure thereby to prevent damageto said levers and the firing member connected thereto as a shock isreceived by the depth charge, the levers of each of said toggle jointsbeing arranged such that their pivotal centers are substantially inalignment whenthe firing memberis in said initial position, and a pairof inertia devices respectively carried by one of said pairs of leversand movable therewith, said inertia devices being adapted to engage thelevers of the other pair respectively when the firing member is in saidinitial position thereby end thereof to said member, a second leverpivotally secured at one end thereof to said first named lever and atthe other end to a su.pport ing member, a yieldable connection betweensaid supporting member and said supporting structure, said levers beingarranged such that their pivotal centers are substantially in alignmentwhen the firing member is in an initial unmoved position, and an inertiadevice carried by one of said levers and arranged thereon, said inertiadevice being adapted to engage the other of said levers thereby toprevent the levers from being moved into a position such that theirpivotal centers are in dead center alignment.

5. In a depth charge of the character disclosed.

the combination of a depth charge pistol having a supporting structureand afiring member adapted to be moved relatively thereto under pressureof the surrounding water into a predetermined firing position thereby tofire the depth charge,. a lever pivotally secured at one end thereof tosaid member, a second lever pivotally secured at one end thereof to saidfirst named lever and at the other end to a support-V ing member, ayieldable connection between said supporting member and said supportingstructure, said levers having the pivotal centers thereof slightly outof alignment when the firing member is in an initial unmoved positionand flexed well out of alignment when in the firing position, and aninertia device carried by one of said levers for maintaining the leversagainst flexing when inertial force is applied to the firing memberthereby to prevent movement of the firing member to the firing position,said inertia I device engaging the other of said levers while in theinitial unmoved position to prevent movement of the levers into aposition such that the pivotal centers thereof are in dead centeralignment.

JOHN L. ANDREWS.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PA'I'EN'IS Great Britain Aug. 27, 1926

